At&t Bell Laboratories

Lucent Technologies Inc.

Fitel USA Corporation

At+t Corp.

Bell Telephone Laboratories

American Telephone & Telegraph Co., At&t Bell Laboratories

Western Electric Company, Inc.

American Telephone and Telegraph, Co.

Carl Raymond Taylor

John Michael Turnipseed

John W Shea

Peter A Weimann

James R Petisce

Kenneth Wade Jackson

Bob J Overton

Jim Jenqtsong Sheu

Clyde Jefferson Lever, Jr

Nathan E Hardwick, Iii

Richard Dalton Small, Jr

Ralph J Darsey

Priya L Tabaddor

J Thomas Chapin

Richard Hartford Norris

Lee L Blyler

David Kalish

Lloyd Shepherd

Albert John Ritger

Charles J Aloisio, Jr

Paul Emilien Neveux, Jr

Lisa M Larsen-Moss

Charles M Leshe

Addison G Hardee, Jr

Daniel Harper, Jr

Arturo Hale

Valerie Jeanne Kuck

Daryl Inniss

Kariofilis Konstadinidis

Manuel R Santana

Alvin C Levy

Richard Norris

Paul F Gagen

Peter Gerald Simpkins

Krishnaswamy Kathiresan

Stephen Clement Mettler

Arthur C Hart

Charles Joseph Aloisio

Charles H Gartside

Robert C Moore

George S Brockway

Shahabuddin Siddiqui

Neil Wilbur Sollenberger

Raymond P DeFabritis

James V Smith, Jr

Jane F Kuhl

Darryl L Brownlow

Peter A Woog

Theodore L Parker

Terrence A Lenahan

John A Rennell, Jr

A coated fiber strand including at least one heterogeneous region present in one or more coating layers. The heterogeneous region(s) preferably comprises a material useful for coding of the fiber. The optical fiber can include a primary coating layer and a secondary coating layer where the heterogeneous region(s) defines one or more colored stripes in or on the secondary coating layer. A method for forming a coated fiber, such as an optical fiber, includes introducing at least one coating layer onto a fiber strand such that one or more coating layers cover a portion of the surface of the strand. At least one heterogeneous region is introduced into or onto one or more coating layers, and the strand is cured to provide a desired product. A desired functionality, e.g., coding, can thus be introduced onto a fiber without adversely effecting subsequent processing steps, e.g., curing of the coating layer(s).

Methods for making coated fiber strands having one or more heterogeneous regions

The outside coating of dual coated optical fibers is improved by the addition of a filler to increase the microbending resistance of the optical fiber. The coating is improved by the addition of very small clay platelets, with the platelets aligned along the fiber axis. It is found that standard polymer coatings can be loaded with enough filler to enhance the mechanical properties, while the particulates are small enough to be essentially transparent to the UV curing radiation.

Optical fiber coatings

A buffer encasement has a longitudinally extending interior surface that extends around and defines a longitudinally extending passage containing a stack of optical fiber ribbons. The interior surface closely bounds the stack, and the buffer encasement is easily removable from the stack. The buffer encasement can be is easily removable from the stack because the buffer encasement is thin and is constructed of a material that is capable of being easily torn. The buffer encasement can be is easily removable from the stack because the buffer encasement defines a longitudinally extending weakened portion that is capable of being more easily torn than the remainder of the buffer encasement. The weakened portion is operative so that when the weakened portion is torn the buffer encasement defines longitudinally extending edges on the opposite sides of the tear. The edges can be separated from one another to define an opening therebetween through which the stack of optical fiber ribbons can be accessed. The buffer encasement can be in the form of a longitudinally extending piece of tape having longitudinally extending opposite edges defining an overlapping configuration so that the tape encloses the stack of optical fiber ribbons. The edges of the tape can be separated to provide a nonoverlapping configuration in which an opening is defined between the edges and through which the stack of optical fiber ribbons can be accessed. Therefore, the edges of the tape can be reclosed, if desired.

Groups of optical fibers closely bound by easily removable buffer encasements, and associated fiber optic cables

An optical module includes a stack of optical fiber ribbons that are within a buffer encasement, such as a thin sheath, that closely bounds the periphery of the stack. The optical modules can be rectangular, so that the optical modules can be readily stacked in a manner that results in a very space efficient fiber optic cable. The optical modules can be tested prior to being incorporated into the fiber optic cable so as to maximize the probability of the fiber optic cable being fully operable. The sheath cushions all of the sides of the stack. In some optical modules, the stack is movable relative to the sheath and the optical fiber ribbons are movable relative to one another. The sheath is preferably sufficiently rigid to maintain the stack in a stacked configuration, and sufficiently flexible to allow the optical fiber ribbons to slide laterally relative to one another so that, in an end elevation view of the stack, the stack and the sheath can transition from a non-skewed configuration to a skewed configuration. The lateral displacement between the optical fiber ribbons in the skewed configuration is different from the lateral displacement between the optical fiber ribbons in the non-skewed configuration. The stack can be in a longitudinally twisted configuration, and the sheath is sufficiently rigid to hold the stack in the longitudinally twisted configuration. Further, the sheath can be thin such that the exterior surface of the sheath defines ridges that correspond to the twist of the stack.

Stacks of optical fiber ribbons closely bound by respective buffer encasements, associated methods, and associated fiber optic cables

A coated fiber strand includes one or more coating layers located directly or indirectly on the strand and at least one heterogeneous region present in or on one or more of the coating layer(s). The heterogeneous region(s) preferably comprises a material useful for coding of the fiber. One particularly preferred embodiment relates to an optical fiber having a primary coating layer and a secondary coating layer where the heterogeneous region(s) defines one or more colored stripes in or on the secondary coating layer. A method for forming a coated fiber, such as an optical fiber, includes introducing at least one coating layer onto a fiber strand such that one or more coating layers directly or indirectly cover at least a portion of the surface of the strand. The method further includes introducing at least one heterogeneous region into or onto a coating layer(s). The fiber can then be treated, e.g., cured so as to provide a desired product. By this method, a desired functionality, e.g., coding, can be introduced onto a fiber without adversely effecting subsequent processing steps, e.g., curing of the coating layer(s).

Coated fiber strands having one or more heterogeneous regions and methods of making the same

A fiber optic cable includes multiple differently sized stacks of optical fiber ribbons. The stacks include a central stack that is approximately centrally located in a jacket passage and peripheral stacks positioned radially around the central stack. A difference exists between the dimensions of the central stack and the dimensions of one or more of the peripheral stacks. Another fiber optic cable has multiple longitudinally extending stacks of optical fiber ribbons that are within a jacket passage. The stacks include a central stack that is approximately centrally located in the jacket passage, and peripheral stacks positioned radially around the central stack. Buffer encasements that respectively contain the peripheral stacks are longitudinally stranded around the central stack. Each buffer encasement includes a longitudinally extending interior surface that extends around and defines a longitudinally extending passage that contains the respective peripheral stack, and each interior surface closely bounds and engages a substantial portion of the periphery of the respective peripheral stack. Another fiber optic cable includes multiple optical modules within a longitudinally extending jacket and longitudinally stranded around a central member. Each optical module includes a stack of optical fiber ribbons enclosed in a buffer encasement. Each buffer encasement includes a longitudinally extending interior surface that extends around and defines a longitudinally extending passage that contains the respective stack, and the interior surface closely bounds and engages a substantial portion of the periphery of the respective stack.

Fiber optic cables with multiple stacks of optical fiber ribbons

Embodiments of the invention include an optical energy transmission system, method and apparatus having improved mode coupling. According to embodiments of the invention, an optical energy transmission medium such as an optical fiber includes a plurality of particles formed in one or more coating region layers surrounding the cladding region and/or one or more buffer region layers surrounding the coating region for inducing microbending thereof, thus promoting advantageous mode coupling, which improves bandwidth potential by reducing dispersion. The method for manufacturing the inventive optical energy transmission medium includes forming one or more coating region layers and/or one or more buffer region layers containing particles such as fumed silica in such a way that particles are maintained within the optical energy transmission medium and form controlled perturbations along the optical fiber that enhance mode coupling to the extent that bandwidth of the optical fiber is improved.

Mode coupling buffered optical fiber apparatus and method for making

Embodiments of the invention include an optical energy transmission system, method and apparatus having improved mode coupling. According to embodiments of the invention, an optical energy transmission medium such as an optical fiber includes bubbles formed therein for inducing microbending of the optical energy transmission medium, thus promoting advantageous mode coupling, which improves bandwidth potential by reducing dispersion. The bubbles are formed, e.g., in one or more buffer region layers and/or at the interface between the coating and buffer regions. The method for manufacturing the inventive optical energy transmission medium includes controllably forming one or more buffer region layers around the coated optical fiber or other transmission medium in such a way that that a desired amount of bubbles is created and maintained within one or more of the buffer region layers and/or at the interface between the coating and buffer regions. The bubbles form controlled perturbations that enhance mode coupling to the extent that bandwidth of the optical fiber is improved. The quantity and size of the bubbles formed in the optical energy transmission medium are controlled by, e.g., the amount of moisture present in the applied coating.

Mode mixing buffered optical fiber apparatus and method for making

An optical fiber &lsqb;,&rsqb; having protective coating materials &lsqb;,&rsqb;, which surround an elongated strand of glass &lsqb;,&rsqb;, is designed for improved strippability. Preferably, the optical fiber includes two layers (primary and secondary) of radiation-cured polymeric materials surrounding the glass fiber. The primary layer has an equilibrium (in-situ) modulus that resides within the range 120 to 500 psi. Additionally, the primary coating has a pull-out force (adhesion) that is less than 1.2 pounds per centimeter of length (lb/cm), and preferably resides within the range 0.5 to 1.0 lb/cm. It has been found that by increasing the equilibrium modulus, delamination resistance is increased. This has allowed designers to decrease pull-out force while maintaining a suitable delamination resistance. As a result, coating materials can now be stripped away from a glass fiber with little or no residue. This is particularly important in situations where a group of such fibers are bound together in an array &lsqb;,&rsqb; by a matrix bonding material &lsqb;

Coated optical fiber with improved strippability

A stack of optical fiber ribbons is enclosed in a buffer encasement having a relatively soft inner portion and an relatively hard outer portion. The inner portion has an interior surface extends around and defines a longitudinally extending passage that contains the stack, and the interior surface closely bounds the stack. The outer portion extends around, closely bounds and contacts the inner portion, and has a modulus of elasticity that is greater than the modulus of elasticity of the inner portion. In accordance with one example of the invention, the inner portion has an exterior surface that extends around and is spaced apart from the passage, and the outer portion has an interior surface that extends around, closely bounds, and engages the exterior surface of the inner portion, whereby the buffer encasement has multiple plies. In contrast, in accordance with another example of the invention, a surface is not defined between the inner portion and the outer portion.

Stacks of optical fiber ribbons closely bound by respective buffer encasements with relatively hard exteriors and relatively soft interiors, associated methods, and associated fiber optic cables

An optical fiber ribbon in which a plurality of optical fibers are held in an array has a matrix material for bonding to the fibers to form the ribbon. The matrix material has certain characteristics which serve to enhance fiber access, among which are an elastic modulus from 600 to 1200 MPa at room temperature, from 100 to 280 MPa at 100.degree. C., and from 15 to 45 MPa at temperatures greater than 170.degree. C. The matrix material swells in ethanol more than 15% by volume within 20 minutes, and is virtually immune to the action of cleaning solvents. The matrix material has a surface tension of 20-35 mJ/m.sup.2 as do the color coding inks which identify the fibers.

Optical fiber ribbon

The present invention continuously monitors the amount of curing radiation available for curing coating material on a moving optical fiber and includes a curing system having a radiation source capable of providing radiation energy for curing coating material on an optical fiber and a reflector system which redirects non-direct radiation back toward the article. An optical fiber which has been provided with a curable coating material is moved along a path of travel through a curing area. The coating material is cured by causing the radiation source to emit energy suitable for curing the curable coating material. The predictable average amount of light energy properly redirected by the reflector system toward the curable article is sensed as the curable coating material is being cured to obtain continuous in-process reading. The average radiation value is obtained by positioning three longitudinally aligned holes adjacent the fiber path and between the fiber and a radiation sensing device. Furthermore, the amount of the light energy available from the reflector system may be sensed at a location which is outside the reflector system to obtain a reference reading. The in-process readings may then be compared with the reference reading to determine the portion of the radiation available from the radiation source which is actually available for curing the curable coating material.

System for continuously monitoring curing energy levels within a curing

Optical fiber and cable performance are assured by a category of UV-cured polyurethane acrylates. Low cost is the consequence of use of the polycarbonate oligomer. Good performance and long life are ascribed to other ingredients of the coatings. Dependence on the hindered phenols for antioxidant protection assures sufficient protection for these inherently stable materials without incurring fiber damage found to result from use of hindered amine antioxidants.

Optical fiber apparatus

A coating system for individual glass fibers of a lightwave communications system has improved strippability, particularly in situations where a group of such fibers are arrayed together in what is known as a ribbon. A preferred embodiment includes two layers (primary and secondary) of polymeric materials surrounding the glass fiber. The primary layer comprises an oligomer (50-80% by weight), a diluent (15-40% by weight), and additives (5-35% by weight). The oligomer comprises polyol 'A,' diisocyanate 'B,' and a hydroxy-terminated alkyl acrylate 'C' having the structure C-B-A-B-C. At least one of the additives contains a non-crosslinked hydrocarbon component (1-20% by weight) having a structure R.sub.1 --(R).sub.n --R.sub.2 ; where R.sub.1, R.sub.2 comprises an alkyl group or an OH group, and R is a combination of C, H or C, H, O. In an alternative embodiment, the need for a diluent is substantially eliminated by using an oligomer having the structure E-D-E where 'D' represents a carboxy-terminated polyol, and 'E' represents a glycidyl acrylate.

Strippable coating for optical fiber

A hermetically sealed optical fiber cable (20) includes a core (21) comprising a plurality of optical fiber ribbons (22,22) disposed within a core tube (30) comprised of a high temperature resistant polymeric material. The core tube is disposed within a hermetic sealing member (40) which comprises a metal of low electrochemical activity having a sealed seam. An outer jacket (50) is disposed about the hermetic sealing member. The core may be filled with a waterblocking filling material (35). The material of the core tube undergoes only limited degradation because of the limited amount of oxygen and/or moisture trapped in the hermetically sealed cable. The filling material and/or other materials of the cable scavenge moisture and oxygen which travel longitudinally of the cable and reach portions of the cable subjected to a high temperature because of a leak in an adjacent steam line. The filling material and/or other materials are such that they cooperate with polymeric materials of the cable to prevent oxygen and humidity from degrading coating material of the optical fiber. Further, the filling material and the core tube are such that degradation of the core tube in the hermetically sealed cable is avoided.

Optical fiber cable which resists damage caused by a hostile environment

Growing community of inventors

Lawrenceville, GA, United States of America

Carl Raymond Taylor